Abstract: Portable electronic devices may be inspected for the presence of explosives using a combination of nuclear quadrupole resonance (NQR) and explosive trace detection (ETD). NQR may be used to detect bulk or sheet explosives while the ETD may be used to detect minute quantities of explosive particulates. An alarm indication may be generated when either the NQR spectroscopy or the ETD detects an explosive material.

Abstract: Small and inexpensive probeheads for use in nuclear magnetic resonance systems, in particular, magnetic resonance relaxometry systems are provided. The design of the magnet-radiofrequency coil configurations within the probeheads is guided by an excitation bandwidth associated with radiofrequency pulses to be applied to a sample.

Abstract: A method of detecting hazardous materials in containers utilizing nuclear magnetic resonance (NMR) technology. The presence of precursors (e.g., H202) and/or nitrogen in the liquid in the container is determined by placing the container in a static magnetic field, exciting the container with electromagnetic pulses having a frequency corresponding to proton NMR and 14N NMR, and receiving radio frequency (RF) signals through a probe. The excitation pulses are configured to enable detection of the presence of precursors and nitrogen in the container, and may comprise a sequence of short RF pulses. The presence of nitrogen and/or explosive precursors is determined by detecting and evaluating NMR measurement signal amplitudes and relaxation times from the received RF signals. An apparatus comprising a magnet that generates a magnetic field and a probe that generates RF pulses and receives NMR measurement signals from the sampled container in accordance with the aforementioned method.

Abstract: A method of detecting hazardous materials in containers utilizing nuclear magnetic resonance (NMR) technology. The presence of precursors (e.g., H202) and/or nitrogen in the liquid in the container is determined by placing the container in a static magnetic field, exciting the container with electromagnetic pulses having a frequency corresponding to proton NMR and 14N NMR, and receiving radio frequency (RF) signals through a probe. The excitation pulses are configured to enable detection of the presence of precursors and nitrogen in the container, and may comprise a sequence of short RF pulses. The presence of nitrogen and/or explosive precursors is determined by detecting and evaluating NMR measurement signal amplitudes and relaxation times from the received RF signals. An apparatus comprising a magnet that generates a magnetic field and a probe that generates RF pulses and receives NMR measurement signals from the sampled container in accordance with the aforementioned method.

Abstract: Small and inexpensive probeheads for use in nuclear magnetic resonance systems, in particular, magnetic resonance relaxometry systems are provided. The design of the magnet-radiofrequency coil configurations within the probeheads is guided by an excitation bandwidth associated with radiofrequency pulses to be applied to a sample.

Abstract: Small and inexpensive probeheads for use in nuclear magnetic resonance systems, in particular, magnetic resonance relaxometry systems are provided. The design of the magnet-radiofrequency coil configurations within the probeheads is guided by an excitation bandwidth associated with radiofrequency pulses to be applied to a sample.

Abstract: Nuclear magnetic resonance systems and methods of use thereof are provided. The systems employ implantable radiofrequency coils (105) and optionally implantable magnets (101). The systems can employ weak permanent magnets and/or permanent magnets that provide magnetic fields that are much less homogeneous than in conventional systems. This allows, for example, for inexpensive and simple probeheads for nuclear magnetic resonance relaxometry with suitable biosensors. The methods of the present invention allow in-vivo magnetic resonance measurements and, in particular, monitoring of analytes and determination of medical diagnostic information, for example, based on determined magnetic resonance parameters.

Abstract: Small and inexpensive probeheads for use in nuclear magnetic resonance systems, in particular, magnetic resonance relaxometry systems are provided. The design of the magnet-radiofrequency coil configurations within the probeheads is guided by an excitation bandwidth associated with radiofrequency pulses to be applied to a sample.

Abstract: Apparatus and method for varying field strength in a magnetic resonance system while keeping a relatively uniform magnetic field distribution. In an embodiment, a two-pole, generally u-shaped magnet assembly generates a static and uniform magnetic field. The magnet assembly includes two facing magnet poles separated by an air gap. Holes may be formed with the magnet poles. The field control rods may be placed at a pre-determined distance into these holes and symmetrically or asymmetrically moved across each magnet poles in a controlled manner to change the magnetic field strength while keeping the uniform magnetic field distribution. Maximum magnetic field strength may occur when the rods are removed. Minimum magnetic field strength may occur when the rods are fully inserted.

Abstract: Apparatus and method for varying field strength in a magnetic resonance system while keeping a relatively uniform magnetic field distribution. In an embodiment, a two-pole, generally u-shaped magnet assembly generates a static and uniform magnetic field. The magnet assembly includes two facing magnet poles separated by an air gap. Holes may be formed with the magnet poles. The field control rods may be placed at a pre-determined distance into these holes and symmetrically or asymmetrically moved across each magnet poles in a controlled manner to change the magnetic field strength while keeping the uniform magnetic field distribution. Maximum magnetic field strength may occur when the rods are removed. Minimum magnetic field strength may occur when the rods are fully inserted.

Abstract: A magnetic resonance imaging apparatus and method having a magnet assembly, which provides substantially flat surfaces of constant magnetic field outside the assembly and a set of magnetic field gradients. One-, two-, and three-dimensional images are rendered. The static magnetic field is virtually uniform within horizontal degrees of freedom and decreases monotonically in a direction away from the surface. An RF probe, for example, a coil, located adjacent the surface, produces a field substantially perpendicular to the static magnetic field. A magnetic field gradient is set to horizontally scan a given level within the sensitive volume. Received magnetic resonance signals are detected by the coil for a depth corresponding to the excitation frequency. As the tuning and excitation frequency is switched to lower values, signals are generated for layers progressively farther from the surface. The RF probe is automatically tuned.

Abstract: A magnetic resonance imaging apparatus and method having a magnet assembly, which provides substantially flat surfaces of constant magnetic field outside the assembly and a set of magnetic field gradients. One-, two-, and three-dimensional images are rendered. The static magnetic field is virtually uniform within horizontal degrees of freedom and decreases monotonically in a direction away from the surface. An RF probe, for example, a coil, located adjacent the surface, produces a field substantially perpendicular to the static magnetic field. A magnetic field gradient is set to horizontally scan a given level within the sensitive volume. Received magnetic resonance signals are detected by the coil for a depth corresponding to the excitation frequency. As the tuning and excitation frequency is switched to lower values, signals are generated for layers progressively farther from the surface. The RF probe is automatically tuned.

Abstract: An apparatus for and a method of single-sided MRI with a palm-sized probe. The probe includes a planar permanent magnet having a gap between the north and south poles of the magnet. Positioned in the gap are an RF coil and a pair of gradient coils. The gradient coils are located on either side of the RF coil. The probe further includes an RF tuning circuit and a gradient input. In use, the pair of gradient coils produce a controlled magnetic field gradient over the field of view thereby improving image resolution.